Protective effect of anti-oxidants on endothelial function in young Korean-Asians compared to Caucasians

Abstract

Background: Previous studies show that Asians have an impaired blood flow response (BFR) to occlusion after a single high fat (HF) meal. The mechanism is believed to be the presence and susceptibility to high free radicals in their blood. The free radical concentration after a HF meal has not been examined in Asians. Further the BFR to heat after a single HF meal in Koreans has not been measured.

Material/methods: This study evaluated postprandial endothelial function by measuring the BFR to vascular occlusion and local heat before and after a HF meal and the interventional effects of anti-oxidant vitamins on improving endothelial function in young Korean-Asians (K) compared to Caucasians (C) with these assessments. Ten C and ten K participated in the study (mean age 25.3±3.6 years old). BFR to vascular occlusion and local heat and oxidative stress were assessed after a single low fat (LF) and HF meal at 2 hours compared to baseline. After administration of vitamins (1000 mg of vitamin C, 800 IU of vitamin E, and 300 mg of Coenzyme Q-10) for 14 days, the same measurements were made.

Results: This study showed that the skin BFR to vascular occlusion and local heat following a HF meal significantly decreased and free radicals significantly increased at 2 hours compared to baseline in K (p<.001), but not in C. When vitamins were given, the BFR to vascular occlusion and local heat before and after HF meal were not significantly different in K and C.

Conclusions: These findings suggest that even a single HF meal can reduce endothelial response to stress through an oxidative stress mechanism but can be blocked by antioxidants, probably through scavenging free radicals in K. Since endothelial function improved even before a HF meal in K, endothelial damage from an Americanized diet may be reduced in K by antioxidants.

Figure 1

Mean ±SD of baseline blood flow (flux) measured during the 4 minutes period of vascular occlusion and the 2 minute period following the release of the occlusion cuff (A) and 6 minutes period of local heat (B) in 10 Koreans and 10 Caucasians.

Figure 2

Mean ±SD of MDA concentration at baseline, after 2 hours of low fat meal, after 2 hours of high fat meal, at baseline with vitamins, and after 2 hours of high fat meal with vitamins in 10 Koreans and 10 Caucasians. * p<0.01 compared to Caucasians.

Figure 3

Mean ±SD of blood flow (flux) after a low fat meal measured during the 4 minutes period of vascular occlusion and the 2 minute period following the release of the occlusion cuff (A, B) and 6 minutes period of local heat (C, D) at baseline and after 2 hours in 10 Koreans and 10 Caucasians.

Figure 4

Mean ±SD of blood flow (flux) after a high fat meal measured during the 4 minutes period of vascular occlusion and the 2 minute period following the release of the occlusion cuff (A, B) and 6 minutes period of local heat (C, D) at baseline and after 2 hours in 10 Koreans and 10 Caucasians.

Figure 5

Mean ±SD of blood flow (flux) measured during the 4 minutes period of vascular occlusion and the 2 minute period following the release of the occlusion cuff (A, B) and 6 minutes period of local heat (C, D) at baseline and at 2 hours after the ingestion of the high fat meal after the intake of vitamins for 14 days in 10 Koreans and 10 Caucasians.

Figure 6

Mean ±SD of baseline blood flow (flux) measured during the 4 minutes period of vascular occlusion and the 2 minute period following the release of the occlusion cuff (A, B) and 6 minutes period of local heat (C, D) before and after the intake of vitamins for 14 days in 10 Koreans and 10 Caucasians.

Figure 7

Mean ±SD of blood flow (flux) after a high fat meal measured during the 4 minutes period of vascular occlusion and the 2 minute period following the release of the occlusion cuff (A, B) and 6 minutes period of local heat (C, D) before and after the intake of vitamins for 14 days in 10 Koreans and 10 Caucasians.

Figure 8

Mean ±SD of blood flow (flux) after a high fat meal measured during the 4 minutes period of vascular occlusion and the 2 minute period following the release of the occlusion cuff and 6 minutes period of local heat before (A, C) and after (B, D) the intake of vitamins for 14 days between 10 Koreans and 10 Caucasians.